Subaru Thermostats & Parts

How a Defective Thermostat Can Damage Your Engine

When the thermostat fails, the engine may run too hot or too cold—either condition can lead to long-term damage, especially in performance vehicles like the Subaru WRX. Left unchecked, a bad thermostat can cause overheating, reduced fuel economy, or even head gasket failure.

What's the Function of the Thermostat in Your Subaru?

The thermostat monitors coolant temperature and opens or closes to regulate its flow between the engine and radiator. It ensures the engine reaches optimal operating temperature quickly and maintains it, which is critical for combustion efficiency, emissions control, and overall performance.

What Causes the Thermostat to Wear Out?

Thermostats can wear out due to age, corrosion, debris in the coolant, or frequent exposure to extreme heat. Performance driving, inconsistent coolant changes, and pressure surges from faulty components like hoses and clamps can also accelerate thermostat failure.

Top Reasons to Replace a Damaged Thermostat Urgently

1. Prevent Engine Overheating

A stuck thermostat can block coolant flow, leading to excessive heat and engine failure.

2. Avoid Poor Fuel Economy

A thermostat stuck open keeps the engine running cold, decreasing fuel efficiency.

3. Protect Your Head Gasket

Overheating from a failed thermostat increases the risk of head gasket leaks or cracks.

4. Maintain Cabin Heat Function

A malfunctioning thermostat can disrupt coolant flow to the heater core, leaving you without heat in colder months.

5. Prevent Sensor and ECU Issues

Fluctuating engine temps can confuse sensors, triggering warning lights and poor throttle response.

Contact us today for genuine Subaru parts at exclusive online discounts.